Keep It Extremely Simple, or 66% of the Population Can’t Use Your Design
Usability guru Jakob Nielsen:
Overall, people with strong technology skills make up a 5–8% sliver of their country’s population, whatever rich country they may be coming from. Go back to the OECD’s definition of the level-3 skills, quoted above. Consider defining your goals based on implicit criteria. Or overcoming unexpected outcomes and impasses while using the computer. Or evaluating the relevance and reliability of information in order to discard distractors.